The present invention relates to a keyboard unit in which a hammer is driven with a key by the pressing operation of the key and the hammer does not operate in synchronization with the key in the pressing/releasing strokes of the key in some cases.
Keyboard musical instruments are available in which a hammer does not operate in synchronization with a key in the pressing/releasing strokes of the key in some cases as typically in keyboard musical instruments having a hammer action or a pseudo hammer action. In this kind of musical instrument, the key and the hammer do not always operate in synchronization with each other, and the relative relationship between the key and the hammer is complicated depending on various key pressing and releasing operation modes, such as the strength and depth of key pressing operation and the timing of key releasing operation. Hence, if the motion of only one of the key or the hammer is detected and musical sound is generated electronically according to the result of the detection, the player of the musical instrument may feel uncomfortable in some cases, for example, because the timing of key pressing operation does not coincide with the timing of sound generation or the strength of pressing the key does not match the volume of the generated sound. Accordingly, keyboard musical instruments are available in which the engagement of members is detected at two or more positions and the result of the detection is reflected to musical sound control.
For example, in JP-A-9-120289, a jack tail sensor is provided on a member equivalent to a regulating button, and a jack sensor is provided on a regulating rail, to detect the timing of the contact between the member equivalent to the regulating button and a member equivalent to a jack and the timing of the contact between the regulating rail and the member equivalent to the jack. Musical sound is then controlled on the basis of the detection results of these two sensors, whereby accurate touch response is obtained.
However, in JP-A-9-120289, the sensors for detecting the timing of the contact are configured as a leaf switch formed of a hollow body made of rubber or a metal spring. Hence, the reaction forces generated by them considerably affect the feeling of pressing the key. Hence, it is desired that the feeling of pressing the key is not affected as much as possible in the case that the various operation states of the key are estimated appropriately so that the estimated states can be reflected to musical sound control and so that performance data can be generated.